Process for killing plant pests using cyanoalkyl-nitrophenyl carbonates

ABSTRACT

Compounds of structure   WHERE R1 is alkyl of one to 10 carbon atoms, and R2 is cyanoalkyl containing from one to four carbon atoms in the alkyl group. These compounds are extremely effective as acaricides and also have fungicidal and herbicidal activity.

United States Patent 91 Van den Boogaart et al.

[451 Mar. 27, 1973 1 PROCESS FOR KILLING PLANT PESTS USING CYANOALKYL-NITROPHENYL CARBONATES [75] Inventors: Krijn Van den Boogaart, Meelis Nicolaus Louis, both of Vlaardingen, Netherlands [73] Assignee: N. V. Fabriek van cliemiscl e Producten Vondelungenplaat, Rotterdam, Netherlands [22] Filed: Mar. 26, 1971 [21] Appl. No.: 128,525

Related US. Application Data [62] Division of Ser. No. 710,630, March 5, 1968, Pat.

[52] US. Cl ..424/301, 71/105 [51] Int. Cl. ..A0ln 9/12 [58] Field of Search ..424/ 301 [56] References Cited UNITED'STATES PATENTS 3,287,211 11/1966 Szabo et al. ..424/30l I 1/1968 Pianka et al ..424/30l ll/1968 Pianka et al ..424/30l Primary Examiner-Albert T. Meyers Assistant Examiner-Frederick E. Waddell Attorney-Robert G. Danehower Where R is alkyl of one to 10 carbon atoms, and R is cyanoalkyl containing from one to four carbon atoms in the alkyl group. These compounds are extremely effective as acaricides and also have fungicidal and herbicidal activity.

3 Claims, No Drawings PROCESS FOR KILLING PLANT PESTS USING CYANOALKYL-NITROPHENYL CARBONATES This application is a division of Ser. No. 710,630, filed Mar. 5, 1968 now US. Pat. No. 3,594,400.

Nitrophenyl carbonates devoid of cyano substituents are known and have pesticidal activity. For example, US. Pat. No. 3,287,61 1 discloses compounds of structure IIIO:

where R is lower alkyl and these compounds have acaricidal activity. Likewise, US. Pat. No. 3,234,260 discloses similar acaricidal compounds which are further substituted in the phenyl ring. US. Pat. No. 3,198,824 discloses as fungicides and herbicides compounds of structure where R is alkyl and Ar is aryl.

It has now been found, however, that surprisingly superior acaricides, herbicides and fungicides are obtained by providing compounds of structure where R is an alkyl group of one to 10 carbon atoms and R is a cyanoalkyl group containing from one to four carbon atoms in its alkyl position.

The compounds of the invention can be prepared by phosgenation of the compound NC-R -Ol-I giving NC- R -OCO-Cl and then reacting this compound with a dinitro-alkylphenol. The same type of compounds can be obtained by reaction of the appropriate chloroformic acid with the appropriate phenolate.

Preparation of the compounds is illustrated as follows:

In a reaction flask, equipped with a stirrer, a thermometer, a dropping funnel and a gas inlet tube; 96

grams of acetone cyanohydrin, (CH C(Ol-l)CN, was mixed with 300 ml. of toluene. During 1 hour, 113 grams of phosgene was introduced at a temperature of 5 to C. Subsequently, 89.5 grams of pyridine was added in 1.5 hours at a temperature of 0 to C. The hydrochloric acid salt of pyridine precipitated. Stirring was continued at a temperature of 0C. for another hour, whereafter air was passed through in order to remove traces of phosgene.

Then 270 grams of 95 percent 2.4-dinitro-6-sec. butylphenol dissolved in 50 ml. of toluene was added. 89.5 grams of pyridine was added dropwise at a temperature of 5 to 10C. The mixture was filtered and the residue washed with toluene. The toluene solution was extracted with water and dried above sodium sulphate.

After removing the sodium sulphate the toluene was vaporized under diminished pressure. The oil so obtained was crystallized from toluene. In this way 157 grams of very light colored crystalline product was obtained which melted at 87C. In this compound R was sec.-butyl and R was -C(CI-I,,) CN.

In the same way the following compounds of the invention were prepared:

Product R1 R2 poi ri ls Methyl CN 108 Sec. butyl CH2CN 76 Do H 74 C lCHa D0 CHZ-CH2CN as Do CN 87 Sec. amyl CHzCN 64 D0 H Oil JOH Do CHzCH2CN Do CN 60 JCHz Sec.octyl CN Oil The compounds dr'the in vention can be processed to form pesticidal preparations by mixing them with solid diluents and if desired with dispersing agents, emulsifying agents or emulsifyable solutions. Generally the wettable powders contain 50 90 weight percent of the active compound and for the rest a dispersing agent, a wetting agent, and a carrier. If the active compound is a liquid or oil, the content of active compound is below 50 weight percent. The liquid compounds are then adsorbed on adsorbing carriers. Emulsifyable solutions can be obtained by the solution of the active compound in a solvent or mixture of solvents. Suitable solvents are alcohols, ketones, ethers, aromatic hydrocarbons and petroleum fractions. As indicated, dispersing agents, wetting agents, or emulsifying agents can be added.

EVALUATION OF coiiirouuos EXAMPLE 1 In a test for determining herbicidal residual action, the active compound was sprayed at concentrations of 4, 2, l, 1.5, and 0.25 kg of active compound per hectare on soil rich in weeds. All compounds were formulated in the same way. The following results expressed as LD in kg active compound per hectare are obtained.

TABLE I Compound coded R R2 LDm A. Sec. butyl 'CH; 0.76 d -CH2CN 0. 55 --CHz-CHz 0.65

ON 0.60 --CH3 III C. do H 5.40

C1 --d0 CN 1.30

gon' 312 ISEZEEZ'CN 5 38 H 5.00 ]OH;

F do ON 0.76

--(i7-QH3 CHa EXAMPLE I] In a test for determining the fungicidal action several compounds were compared. Tests were carried out on gherkins infected with mildew by spraying the formulations containing 80, 40, 20, and 10 ppm of the active compounds. The degree of mildew covering was determined after 10 and 14 days. The numbers shown in Table II are the average of the results.

The excellent fungicidal activity of the compounds, particularly cyanoisopropyl-2.4-dinitro-6-sec. amylphenylcarbonate (F is clearly shown.

EXAMPLE in The examination of the acaricidal action was carried out on mites of the genus Bryodia on leaves of the brown bean. Leaves were sprayed in Petridishes with aqueous formulations of the active compounds in concentrations of 200, 40, and 8 ppm in a quantity corresponding to 1,000 liters per hectare. Before the leaves were sprayed 25 living mites were present on each leaf. Tests were carried out in quadruple; after 1 and 2 days the dead mites were counted.

The numbers in Table III represents the percentage of dead mites.

TABLE III DEAD MITES Concentration in ppm Compound 200 40 8 A 100 98 97 C 100 83 23 C, 100 100 100 F 100 8 F, 100 96 2.4-dinitro-6-sec. butyl-phenolester of fi.B-dimethylacrylie acid (a commercial acaricide known as ACRIDIC 100 27 It is quite clear from the results shown in Table III that the compounds of the invention are excellent acaricides. I 1

The compounds of the invention appear to be partieularly suitable for a'combined acaricidal and fungicidal action and preferred species of useful compounds are those identified above as C, and F It will be understood that numerous changes and variations may be made without departing from the spirit and scope of the invention.

We claim:

1. The process for killing plant pests selected from the group consisting of fungi and acarids which comprises contacting said pests with a pesticidal amount of a compound of the formula where R is alkyl of one to 10 carbons and R is cyanoalkyl containing from one to four carbons in the alkyl group.

2. The process of claim 1 where the active agent is Sec-04H 3. The process of claim 1 where the active agent is Nor- 

2. The process of claim 1 where the active agent is
 3. The process of claim 1 where the active agent is 